低温厌氧氨氧化生物滤池群落结构分析

为了解低温(150～165 ℃)稳定运行的厌氧氨氧化生物滤池微生物特征,利用扫描电镜(SEM)、变性梯度凝胶电泳技术(DGGE)和克隆测序等方法,对低温稳定运行的两个上流式厌氧氨氧化生物滤池进行微生物群落结构分析．SEM结果显示,陶粒填料反应器(B1)内丝状菌较多,球形细菌分布密度较低,而火山岩填料反应器(B2)没有发现丝状菌,球形细菌分布密集．DGGE结果表明,B1与B2反应器微生物种类有所差别,种群相似性为681％,B2反应器内细菌丰度更高,但两反应器内厌氧氨氧化细菌种类相同．通过细菌及ANAMMOX菌16S rRNA克隆测序,鉴定反应器内厌氧氨氧化细菌为Candidatus Kuenenia stuttgartiensis．采用火山岩填料生物滤池反应器形式,并富集Candidatus Kuenenia stuttgartiensis,有助于厌氧氨氧化工艺在较低温度(150～165 ℃)条件下稳定运行和推广应用．     

解体好氧颗粒污泥强化修复及其微生物群落演替特征

通过在解体的好氧颗粒污泥中投加硫酸铝来强化颗粒的再形成过程,并对期间微生物的群落演替特征进行了分析。结果表明,硫酸铝的投加加速了解体颗粒污泥的再形成,并且再形成的颗粒污泥具有更加良好的污泥特性和更高的细菌总数。在强化修复过程中,颗粒污泥中的优势菌群主要分布于变形菌门(Proteobacteria),其中假单胞菌(Pseudomonas)是Proteobacteria中的主要菌属。     

Comparison of hydrogen-producing bacterial communities adapted in continuous and discontinuous reactors

We evaluate the bacterial composition during the anaerobic granules adaptation for hydrogen production using continuous and discontinuous feeding-regime. Adaptation was induced by employing short hydraulic retention times and low pH. The microbial community analysis revealed that both discontinuous and continuous adaptation strategies resulted in the selection of different microorganisms despite the use of the same initial inoculum. The dominant microorganisms present in the continuous process belong to the genus Escherichia and Clostridium; while in the discontinuous adaptation prevailed Clostridiales. The different feeding-regimes applied not only reduced the diversity, but also the composition of the microbial community. The Jaccard's and Shannon–Wiener indexes showed that the different operational strategies applied not only reduced the diversity, but also the composition of the microbial community.     

A/A/MBBR工艺处理混合污水的脱氮除磷中试研究

采用A/A/MBBR工艺处理由粪便液和生活污水组成的混合污水,试验条件:填料投配比为20%,好氧池1和好氧池2中的填料体积比为1:3,好氧池的水力停留时间为5 h,混合液回流比为120%,污泥回流比为60%,泥龄为6 d,好氧池的溶解氧为3.0 mg/L,温度为16～20℃.系统稳定运行一个月的结果表明:脱氮除磷效果及对有机物的去除效果均稳定而良好,出水氨氮、总氮、总磷和COD平均浓度分别为0.3、12.9、0.35和36.22 mg/L,均达到了国家一级A排放标准.     

Effect of carbendazim and pencycuron on soil bacterial community

Soil bacterial composition is used as one of the important indicators of negative effects of the use of pesticides in agriculture. Very little is known on the effects of fungicides, particularly carbendazim and pencycuron on soil bacterial community. In this study, laboratory experiments were conducted to examine the effects of various concentrations of carbendazim and pencycuron on diversity of bacterial community in soils collected from strawberry field and incubated at different temperature conditions. The degradation rate of fungicides both in sterile and non-sterile soils were also investigated. Residues of fungicides were measured using high performance liquid chromatography (HPLC) and the change in bacterial community was examined by comparing the 16S rDNA bands on patterns by denaturing gradient gel electrophoresis (DGGE). The dissipation of carbendazim was affected by concentration applied, whereas that of pencycuron was affected by both concentration applied and incubation temperature. The microbial community could recover to its previous composition after 126 days of cultivation with the application of 10 mg/kg of carbendazim but not with the application of a high concentration, 100 mg/kg, of pencycuron. From cluster analysis, the bacterial community structure showed approximately 50% similarity throughout the experimental period, which indicated that the soil microbiota composition was not stable throughout the 120 cultivation days.     

PCR‐DGGE analysis on microbial communities in pit mud of cellars used for different periods of time

Polymerase chain reaction denaturing gradient gel electrophoresis (PCR‐DGGE) was used to analyse microbial community evolution in the pit mud of cellars used for different periods of time in production of Chinese Luzhou‐flavour liquor. The pit mud was collected from the cellars and the microbial DNA was extracted from the microbes in the pit mud. The Bf 968 primer was used for PCR‐DGGE to analyse the variable region 6 (V6) to variable region 8 (V8) of the microbial 16S rDNA. It was found that the band number, dominance, diversity and similarity of the 16S rDNA were clearly different in the DGGE patterns, because of the great diversity expressed by the different microbial communities in the different‐aged cellars. It is concluded that mutual collaboration and constraint exist between the different microbial communities in the different‐aged cellars, and this relationship leads to an evolutional change in the structures and in the numbers of the microbial communities in the pit mud of the cellars. Changes become more obvious with increasing age of the liquor cellars. Copyright © 2012 The Institute of Brewing & Distilling     

Comparison of planktonic and reed biofilm bacteria in different riverine water bodies of river Danube

As the submerged shoot parts of common reed (Phragmites australis) can provide large surfaces for biofilm‐forming bacteria, extensive reed stands can effectively contribute to the self‐purification in the littoral zones of freshwaters. However, bacterial biofilm developed on reed surfaces have been studied only in still waters. In the present study, comparative examinations were performed on the planktonic and reed biofilm bacterial communities from two different riverine water bodies. Water and reed biofilm samples were taken at the beginning and end of the vegetation period from (a) a regulated side arm and (b) a separated oxbow of River Danube. Besides measuring physical and chemical environmental variables, planktonic bacterial cell numbers were detected by 4′,6‐diamidino‐2‐phenylindole staining method, and the bacterial communities were compared by denaturing gradient gel electrophoresis. Our results demonstrated that the structure and composition of bacterial communities correlated with different environmental variables and were different regarding both the habitats (planktonic vs. reed biofilm) and the types of riverine water bodies. The seasonal differences in the bacterial community structures were smaller in the river side arm than in the separated oxbow. In the water column, representatives of widespread and typical freshwater planktonic bacteria (“Candidatus Planktophila,” Limnohabitans, and Polynucleobacter), whereas, in the reed biofilm samples, phototrophic and plant associated bacteria were identified.